The balloons are deflated, the confetti has been swept away. Now that that the 2012 election is past, the thing that unites almost all of the winning candidates, nationally and statewide, is their major party label. The congressional delegation and the state legislature are made up of either Democrats or Republicans. Yet Oregon does have a handful of minor parties who field candidates. The parties who ran candidates for president got under two percent of the vote at best.

What are the factors that maintain the current system of major party dominance? Why does so much of the electorate keep voting for Rs and Ds when many say they are fed up with the two party system and a growing number choose to register (pdf) as unaffiliated or with another political party?